Imaging-based diagnosis for extraskeletal Ewing sarcoma in pediatrics: A case report

Figure 1. Sonography of the soft tissue mass in the neck. A and B: At the grey scale images, a soft tissue mass consisted of hypoechoic and anechoic was found in the right neck with the measurement of 33 mm × 27 mm × 28 mm on the longitudinal section and transection; C: Internal vascularity was present on Doppler images.

Figure 2. The soft tissue mass was indicated on the transverse plane, coronal plane and sagittal plane from 3.0 T magnetic resonance imaging scan. A: A well-defined lesion located in the right laryngeal and piriform recess present as heterogeneous equisignal intensity on T1 -weighted image; B, D and F: High signal intensity on T2 -weighted images; C, E and G: Moreover, the contrast enhanced MRI scan displayed the prominent and heterogeneous contrast enhancement with fast perfusion mode in the early arterial phase on T1+C images.

Figure 3. Pathological gross images of the lesion. A: The dark red mass was completely enveloped in well-defined capsule; B: It was elucidated to be multilocular cystic when split.

Figure 4. Histologic specimen (immunohistochemical stain, immunohistochemistry; original magnification, × 400) confirmed a diagnosis of the extraskeletal Ewing sarcoma, with the small round blue-stained cells observed. Immunochemical histological findings: NSE(+), NF(-), INI-1(+++), TTF-1(-), CK20(-), TDT(-), Wilms tumor(-), Bcl-2(+++), Ki-67(+), CD34(-), CD99(+++), Vimentin(+++), Syn(+).